Peel, slice and lay the bananas in a single layer on a parchment paper or silicone mat lined baking sheet. Freeze for at least 2 hours or overnight.

Once frozen, purée the banana slices in a blender (like the Blendtec) or food processor until smooth (If they have been freezing for overnight, allow them to sit out for 10 minutes until you purée).

Scoop the banana soft serve in a freezer safe container and press plastic wrap against the top of the soft serve and freeze for at least 1 hour or until mostly firm.

Meanwhile, make your cookies by first preheating the oven to 375°F.

Whisk the flour, baking soda, baking powder and salt together in a small bowl.

In a large bowl with an electric beater, beat the sugar, brown sugar and coconut oil until combined.

In a small bowl, stir the ground flaxseed and water together. Add it to the sugar mixture and beat until combined. Beat in the milk and vanilla.

On low speed, beat in the dry ingredients until just combined. Stir in the chocolate chips.

Scoop out by the 2-3 tablespoons onto a parchment paper or silicone mat covered baking sheet. Shaping the dough into a circle and slightly press down the top with the palm of your hand.

Bake for 8 minutes or until the edges are light brown. Allow the cookies to cool completely before freezing the cookies for at least 1 hour.

Once the cookies are frozen and the soft serve is firm, assemble the cookies by first matching up like-shaped cookies. Scoop soft serve on one cookie and gently press down on top of the soft serve with the other cookie.

Freeze the sandwiches for at least one hour. Once frozen, either serve or wrap the sandwiches individually in plastic wrap and keep in the freezer for up to 1 month.